Figure 2. (a) Mn 2p, (b) Mo 3d, (c) Fe 2p, (d) Zn 2p and (e) O 1s XPS data of the ZnO@Mo-Fe-MnO2 NAs. (f) TEM, (g) STEM,(h, i) HRTEM images, (j-n) corresponding EDX elemental mappings at Mn, Mo, Fe, Zn, O regions of the ZnO@Mo-Fe-MnO2 NAs, respectively.